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Bouaziz M.,Unite de Physique des Dispositifs Semi conducteurs | Ouerfelli J.,Unite de Physique des Dispositifs Semi conducteurs | Srivastava S.K.,India Institute of Technology | Bernde J.C.,LaMP | Amlouk M.,Unite de Physique des Dispositifs Semi conducteurs

Cu2SnS3 thin film have been synthesized by solid state reaction under vapour sulphur pressure at 530 °C, during 6 h, via a sequentially deposited copper and tin layers Cu/Sn/Cu...Sn/Cu/Sn. The structure and the composition were characterized by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Electron Probe Micro Analysis (EPMA). X-ray diffraction revealed that as the deposited film crystallizes in the cubic structure and the crystallites exhibit preferential 111 orientation of the grains. Moreover, EPMA analysis confirmed that the obtained film is stoichiometric. The SEM study shows the presence of spherical particles of ≈100-120 nm diameters. The optical absorption coefficient and band gap of the film were estimated by means of transmission and reflection optical measurements at room temperature. A relatively high absorption coefficient in the range of 104 cm-1 was indeed obtained and the band gap value is of the order of 1.1 eV. On the other hand, the electrical conductivity of Cu2SnS3 film prepared in the present experiment is suitable for fabricating a thin film solar cell based on not cheaper and environmental friendly material. © 2010 Elsevier Ltd. All rights reserved. Source

Benchouk K.,Oran University of Science and Technology - Mohamed Boudiaf | Zamallach K.,Oran University of Science and Technology - Mohamed Boudiaf | Khelil A.,Oran University of Science and Technology - Mohamed Boudiaf | Bernede J.C.,LaMP
IOP Conference Series: Materials Science and Engineering

Thin films of CuAlTe2 were elaborated by a sequential deposition of three elements Cu; Al and Te under secondary vacuum on glass slides followed by an annealing of 1/2 hour in an open tube within argon atmosphere. The X-rays diffraction diagram depicts a (112) preferential orientation and the presence of low intensities peaks characterizing the chalcopyrite structure. This shows that the majority of crystallites are directed towards the (112) direction with an orientation factor having an approximate value of 70 %. The height of the crystallites has been assessed using a scanning electron microscope and found to be larger than 200nm. © 2010 IOP Publishing Ltd. Source

L.A.M.P. | Date: 1981-11-16


Jonnalagedda M.,LaMP | Stucki S.,LaMP | Rompf T.,LaMP | Odersky M.,LaMP

Parsers are ubiquitous in computing, and many applications depend on their performance for decoding data efficiently. Parser combinators are an intuitive tool for writing parsers: tight integration with the host language enables grammar specifications to be interleaved with processing of parse results. Unfortunately, parser combinators are typically slow due to the high overhead of the host language abstraction mechanisms that enable composition. We present a technique for eliminating such overhead. We use staging, a form of runtime code generation, to dissociate input parsing from parser composition, and eliminate intermediate data structures and computations associated with parser composition at staging time. A key challenge is to maintain support for input dependent grammars, which have no clear stage distinction. Our approach applies to top-down recursive-descent parsers as well as bottom-up nondeterministic parsers with key applications in dynamic programming on sequences, where we auto-generate code for parallel hardware. We achieve performance comparable to specialized, hand-written parsers. Source

Baumgardner D.,National Autonomous University of Mexico | Brenguier J.L.,CNRM | Bucholtz A.,U.S. Navy | Coe H.,University of Manchester | And 14 more authors.
Atmospheric Research

An overview is presented of airborne systems for in situ measurements of aerosol particles, clouds and radiation that are currently in use on research aircraft around the world. Description of the technology is at a level sufficient for introducing the basic principles of operation and an extensive list of references for further reading is given. A number of newer instruments that implement emerging technology are described and the review concludes with a description of some of the most important measurement challenges that remain. This overview is a synthesis of material from a reference book that is currently in preparation and that will be published in 2012 by Wiley. © 2011 Elsevier B.V. Source

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